GB2033468A

GB2033468A - Door closing devices

Info

Publication number: GB2033468A
Application number: GB7928575A
Authority: GB
Original assignee: Nippon Electric Industry Co Ltd
Current assignee: Nippon Electric Industry Co Ltd
Priority date: 1978-08-19
Filing date: 1979-08-16
Publication date: 1980-05-21
Also published as: US4325164A; IT1122795B; IT7925162A0; FR2433627B1; FR2433627A1; DE2933555C2; GB2033468B; DE2933555A1

Description

1 GB 2 033 468A 1

SPECIFICATION

Improvements in pivot hinges having door closing devices This invention relates to door closing devices, and, in particular, to pivot hinges having door closing devices releasably mounted thereon.

There is a known pivot hinge which com prises a plate having a pivot pin secured thereto and another plate pivotally mounted on the pivot pin. One of these plates is mounted on the floor or the door frame and the other on the door. Thus, the door is rotatable about the pivot axis for opening and 80 closing.

A known kind of such a pivot hinge is an offset pivot hinge, wherein the pivot pin is disposed offset from the door.

A door hinge is sometimes required to have an automatic door closing mechanism. In the existing pivot hinges which have door closing mechanism, the mechanism is assembled onto one of plates of the hinge or within a housing secured to the plate. Installing a door using hinges having such door closing mechanisms is difficult because of the existence of door closing torque. The large volume of the hinge also makes the installation difficult.

When automatic door closing is required for doors using conventional pivot hinges, it is necessary to exchange the used hinges for hinges having door closing mechanisms.

According to the present invention there is provided a pivot hinge having a door closing device releasably mounted thereon, wherein said pivot hinge has a first plate member for securing to one of a door and a floor or a door frame, pivot pin secured to said first plate member, and a second plate member for securing to the other of the door and the floor or the door frame, the second plate member being pivoted on said pivot pin, and said closing device comprises an outer sleeve which is releasably mounted on one of said second plate member and said pivot pin, an inner member which is mounted in said outer sleeve for rotation relative to said outer sleeve and is releasably connected to the other of said second plate and said pivot pin, and a spring member which is disposed within said outer sleeve, said spring member being connected between said outer sleeve and said inner member so that said spring member may be deformed by a relative rotation between said outer sleeve and said inner member to provide a door closing torque.

According to the invention there is also provided an offset pivot hinge having a door closing device releasably mounted thereon, wherein said offset pivot hinge has a first plate member for securing to one of a door and a floor or a door frame, a pivot pin secured to one end portion of said first plate member, and a second plate member for securing to the other of the door and the floor or the door frame, the second plate member being pivoted at one end portion thereof on said pivot pin, and said closing device comprises an outer sleeve which is releasably mounted at one end thereof on said second plate member, and inner member which is mounted in said outer sleeve for rotation relative to said outer sleeve and is releasably connected to said pivot pin, and a coil spring member which is dispose within said outer sleeve, one end of said spring member being connected to said outer sleeve and the other end of said spring member being connected to said inner member so that said spring member may be twisted by a relative rotation between said outer sleeve and said inner member to provide a door closing torque.

Suitably, the door closing device has a mechanism for reducing the door closing speed..

Preferably, the door closing speed is readily adjustable.

The door closing device may include a mechanism for keeping the door open at a predetermined door opening angular position. The door closing device may have a mecha- nism for presetting the door closing torque sufficient to completely close the door after installing the door using the hinge.

An easily removable set screw may be used for securing the outer sleeve to the second plate.

When the door closing device is mounted on the pivot hinge, the inner member is preferably connected to the pivot pin, and the outer sleeve is preferably connected to the second plate, which is pivoted onto the pivot pin. Accordingly, the relative rotation of the pivot pin and the second plate due to the door opening causes relative rotation of the inner member and the outer sleeve so that the coil spring is twisted. The restoring force of the coil spring provides the door closing torque.

If the connection between the door closing device and the pivot hinge is made by a connection between the outer sleeve and the second plate and between the inner member and the pivot pin and by the use of a set screw, the operations of mounting the door closing device on the pivot hinge and removing the door closing device from the pivot hinge are readily carried out.

The closing device may advantageously have a mechanism for reducing the door closing speed which comprises an oil containing cylinder member and a piston member fitted into the cylinder member. The cylinder member is secured to the inner member and is rotatably supported within, and relative to, the outer sleeve. The piston member is reciprocable within the cylinder upon relative rotation of the inner member and the outer sleeve.

2 GB2033468A 2 The piston member is provided with a check valve which permits a unidirectional oil flow from a first side to a second side of the piston member, and an oil hole which permits oil flow in both directions between respective opposite sides of the piston member. The check valve prevents the oil from flowing therethrough at a time when the piston mem ber moves in a direction corresponding to door closure. Thus, the door closing speed is reduced.

Suitably, an adjuster rod extends through the oil hole of the piston. The adjuster rod is milled to form a tapered surface and an oil passage extends through the oil hole, along side the tapered surface. The adjuster rod is non-rotatably but axially slidably connected to a manually operable rod which is rotatably secured to the outer sleeve. The oil passage alongside the tapered surface in the oil hole may be adjustable by manual operation of the manually operable rod. Thus, the door closing speed is adjustable.

The door closing device may advantage ously have a preset mechanism for keeping the coil spring in a twisted condition in order to provide a door closing torque sufficient to completely close the door. The preset mecha nism comprises a preset screw for fixing the outer sleeve and the inner member in such conditions that the coil spring is twisted by a predetermined angle. After installing the door using the pivot hinge and assembling the door closing device onto the hinge, sufficient door closing torque is obtained by loosening the preset screw.

The door closing device may advantage ously have a door stopper mechanism for keeping the door open at a predetermined angular position. The door stopper mechanism 105 comprises a ring member which is axially slidably connected to the inner member and has at least one axial projection at a predeter mined angular position. A spring member is disposed within the outer sleeve to urge the 110 ring member in the direction of the axial projection. At least one pin member is secured to the outer sleeve so that the pin member may ride over the axial projection against the biasing action of the spring member during 11 relative rotation of the outer sleeve and the inner member.

Suitably, the door stopper mechanism com prises a first ring member fixedly secured into the outer sleeve and having at least one 120 depression formed in an inside surface thereof. A second inner ring member is fixedly secured on the inner member and is disposed inside the first ring with an annular gap therebetween. The second ring member has at least one groove of a depth equal to the depth of the depression of the first ring member but smaller than the width of the annular gap, and at least one stopper depression of a depth smaller than the groove, in the outer surface thereof. At least one roller member having a diameter equal to the total amount of the depth of the groove and the annular gap is disposed in the groove. A retainer ring having at least one roller pocket is rotatably disposed within the annular gap. One end of the coil spring is directly connected to the retainer ring. Therefore, the retainer ring is urged to become in contact with the roller. Since the roller is received in the groove of the second inner ring, the coil spring is connected through the retainer ring, the roller and the second inner ring. Accordingly, the coil spring is twisted by the relative rotation of the outer sleeve and the inner member. During relative rotation, when the depression of the first ring reaches the roller in the groove, the roller goes into the depression and moves together with the first ring. During further rotation, when the roller arrives the stopper depression of the second inner ring, the roller is partially removed from the depression of the first ring and is also received in the stopper depression. Accordingly, the relative rotation of the first ring and the second inner ring is restricted by the roller so that the door may be kept open.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a sectional view of an embodiment of this invention; Figure 2 is a sectional view along the line 11-11 in Fig. 1; Figure 3 is a sectional view of the pivot hinge in Fig. 1 with the door closing device removed but with a cover plate mounted; Figure 4 is a sectional view of another embodiment of this invention; Figure 5 is a sectional view along the line V-V in Fig. 4; Figure 6 is an elevational view of the inner cylinder member including the door stopper mechanism in Fig. 5, which is shown with a partial sectional view; Figure 7 is a developed view of the door stopper mechanism in Fig. 4; Figure 8 is a sectional view of a further embodiment of this invention; Figure 9 is a sectional view along the line 5 W-[X in Fig. 8; Figures 10- 13 are sectional views similar to Fig. 9 but partially omitted, which illustrate conditions at different door opening angular positions; and Figure 14 is a sectional view similar to Figs. 11 -13, which illustrates the preset mechanism.

Referring to Figs. 1-3, in which an embodiment of this invention is shown, a pivot hinge 10 comprises a seat plate 11 to be fixed onto a floor under the door, or a door frame 20. The seat plate 11 has a vertical pin 12 defining a pivot axis, on which a door supporting plate 13 is rotatably and pivotally mounted through a thrust ball bearing 14 and 1 3 GB2033468A 3 a radial bearing 15.

Pivot pin 12 is fixedly secured onto a surface of an end portion 111 of seat plate 11, the other end portion 112 of which is provided with bolt inserting holes 11 a for receiving bolts a fix the seat plate 11 to the floor. Door supporting plate 13 is provided with an hole 1 3a at an end portion 131 thereof in which the radial bearing 15 is fixedly mounted, and with bolt inserting holes 1 3b at the other end 132 thereof for receiving bolts to fix the supporting plate 13 on the bottom surface of the door 21. Thus, the door 21 is supported on the pivot hinge 10 to pivotally rotate about the pivot axis.

A door closing device 30 is easily romovably attached on the pivot hinge 10.

The door closing device 30 comprises an outer sleeve or housing 31 to be connected with door supporting plate 13, and an inner cylinder member 32 to be connected to the pivot pin 12, which is disposed in, and rotatable in relation to, the outer sleeve 3 1. A coil spring 33 is disposed around inner cylinder member 32, with an end of the spring being connected to outer sleeve 31 and with the other end being connected to inner cylinder member 32, so that the spring is twisted by opening the door. The restoring force of the twisted spring provides the door closing torque.

In the shown embodiment, a ring member 34 is secured by a pin 35 in an upper end of outer sleeve 31, and the upper end of coil spring 33 is secured by a pin 36 to the ring 34. A hollow damper shaft 37 is fixedly disposed in outer sleeve 31 and is secured by the pin 35 to the upper ring 34 at the upper end thereof.

Inner cylinder member 32 comprises a cyl- 105 inder head ring 321 which is rotatably mounted on damper shaft 37, a tubular mem ber 322 which is secured by pins 38 to the cylinder head ring 321 at the upper end thereof, and a cup member 323 which is fitted onto, and welded to, the lower end of the tubular member 322. Lower cup member 323 is provided with a groove 323a in the upper surface at the peripheral portion, in which the lower end of coil spring 33 is engaged.

Outer sleeve 31 is provided with a lower cap member 39 in a ring form which is formed with projections 39a downwardly ex- tending on the bottom surface thereof. Cup member 323 is also provided with a central projection 323b downwardly extending through the central hole of the ring like lower cap member 39. The projection 323b is pro- vided with a depression 323c in the projecting end for receiving pivot pin 12 when the device 30 is attached to the pivot hinge 10.

Referring to Fig. 2 in addition to Fig. 1, end portion 131 of door supporting plate 13 is provided with a depression 1 3c for receiv- 1 ing projection 323b of cup member 323, and recesses 1 3d for receiving projections 39a of ring like lower cap member 39, in the upper surface thereof. Pivot pin 12 upwardly ex- tends through a center of, and above, the bottom surface of depression 1 3c, and the extended end portion 1 2a is partially cut away to form a non- annular peripheral surface as shown in Fig. 2. The depression 323c of the projection 323b is consistent with the nonannular form of the extending end 1 2a of pivot pin 12 so that any relative rotation between pivot pin 12 and lower cup member 323 may be prevented at a time when the extending end 1 2a of pivot pin 12 is received, or fitted, in the depression 323c of lower cup member 323. On the other hand, when the projections 39a of lower ring like cap member 39 are received in the recesses 1 3d of door supporting member 13, outer sleeve 31 is prevented from rotating in relation to door supporting plate 13.

Accordingly, when the door closing device 30 is attached to the hinge 10 by inserting the projections 39a of ring like lower cap member 39 into the recesses 1 3d of door supporting plate 13 and by inserting the pivot pin end 1 2a into the depression 323c of cup member 323, coil spring 33 is twisted by door opening, and the restoring force of the coil spring serves to close the door.

In order to prevent the door closing device from automatically removing from the pivot hinge during use, set screws 16 are provided to door supporting plate 13, by which the projections 39a of ring like cap member 39 is fixedly secured to door supporting plate 13 in the state that projections 39a are received in the recesses 1 3d of door supporting plate 13.

As above described, the door closing device 30 is readily attached to the pivot hinge 10 and is also readily removed from the pivot hinge 10. Therefore, door installing operation is ready because it is performed using the pivot hinge without the door closing device. The door closing device can be readily attached to the hinge if desired. And it can be readily removed at any time when it is not desired.

In non-use of the door closing device, a cover plate 40 is attached to the end portion 131 of the door supporting plate 13 to cover the upper surface including the depression 1 3c and recesses 1 3d, and the pivot pin 12, as shown in Fig. 3.

In the shown embodiment, a set screw 41 is radially screwed in ring like lower cap member 39 to selectively prevent lower cup member 323, and therefore inner cylinder member 32, from rotating in relation to outer sleeve 3 1, in order to preset the door closing torque, or the restoring force of the coil spring 33. Thus, the door closing device is presettable to keep the coil spring 33 is twisted condition prior to shipment from the plant, by 4 GB 2 033 468A 4 rotating the lower cup member 323 in relation to the outer sleeve 31 to twist the coil spring 33 and then screwing the screw 41 to prevent rtation of the cup member 323 in relation to the outer sleeve 31. After the door closing device 30 is attached to the pivot hinge 10, the restoring force of the twisted coil spring 33 is transmitted to the door supporting plate 13 by removing the set screw 41.

In order to prevent the door from quickly closing by the restoring force of the coil spring, the shown embodiment is provided with a torque damping mechanism.

Tubular member 322 of cylinder member 32 is provided with a helical groove 322a threaded in the inner surface thereof. A piston member 42 screw-threaded in the outer surface thereof as shown by 42a is fitted within the tubular member 322, with the outer thread 42a mating the helical groove 322a. The piston member 42 is a hollow body, in the hollow portion of which the lower end portion of damper shaft 37 extends. The damper shaft 37 slidably but non-rotatably guides the piston member 42 by spline connection therebetween. Thus, piston member 42 is upwardly or downwardly moved along damper shaft 37 by rotation of cylinder mem- ber 32 in relation to outer sleeve 31.

The hollow piston member 42 is closed by a valve plate 421 welded thereto at the lower end thereof. The valve plate 421 may be formed as an integral body of the piston member. The valve plate 421 is provided with 100 a small hole 421 a accompanied by valve ball 422 and another small hole 421 b. Damper oil 43 is contained in cylinder member 32, to damp the movement of piston member 42, whereby the door closing speed is decreased.

In door opening, piston member 42 moves upwardly in the shown embodiment, damper oil 43 flows through holes 421 a and 421 b downwardly. When door is closed, piston member 42 moves downwardly. At the time, damper oil flows upwardly through hole 421 b, but the other hole 421 a is closed by valve ball 422. Thus, valve ball 422 constitutes a check valve. Accordingly, oil flow is limited by the check valve in door closing operation, whereby moving speed of piston member 42 is limited. Therefore, the door closing speed is damped.

The door closing speed is adjustable by controlling an adjuster rod 44. The adjuster rod is milled to form a tapered surface 44a, and extends through the hole 421 b to establish an oil passing gap along the milled tapered surface 44a. The upper end of adjuster rod 44 is secured to a screw 45 which screwed into a central hole 37a of damper shaft 37. The screw 45 is formed with a central square hole 45a in which rod 46 is slidably fitted. The square rod 46 extends upwardly through the central hole 37a of the damper shaft 37, and is rotatably fixed to damper shaft 37 in the upper end portion thereof. The square rod 46 is formed with a groove 46a in the upper end surface for receiving a screw driver bit. Therefore, when square rod 46 is rotated by use of screw driver, screw 45 and adjusted rod 44 are rotated and moved upwardly in dependence on the rotating direction of square rod 46.

Accordingly, the oil passing gap along the tapered surface 44a of adjuster rod 44 in the hole 421 b adjustably changed.

The use of the tapered surface of adjuster rod has another advantage that greater damp- ing effect is obtained at the greater door opening angular position.

In Fig. 1, 47 is a top cap, 48, 49 and 50 are 0-rings for sealing the inner bore of the cylinder member 32, and 51 is a thrust washer for receiving the cylinder member.

Referring to Figs. 4-7, another embodiment shown is similar to the above described embodiment, except that a door stopper mechanism is assembled and that door clos- ing device is removably attached to pivot hinge by a different arrangement. For purpose of simplification of description, similar parts are shown by the same reference characters as in Figs. 1-3, and the description of the similar parts will be omitted.

The upper surface of the end portion 131 of door supporting plate 13 is formed flat.. Above the flat surface, non-annular extending end 1 2a of pivot pin 12 projects. The peripheral end surface of the end portion 131 is formed non-annular, as shown by 131 a.

The lower end of outer sleeve 31 partially extends downwardly as shown by 31 a to have a non-annular inner surface consisting with the non-annular peripheral end surface 131 a of door supporting plate 13.

Lower cup member 323 of inner cylinder member 32 is supported through a thrust washer 51 on a plurality of fingers 31 b which radially inwardly project on the inner surface of outer sleeve 31 near the lower end thereof. Projection 323b downwardly projecting from the lower cup member 323 and having nonannular depression 323c for receiving pivot pin end 1 2a is formed with such a stepped outer surface 323d as comprising two arcuate surfaces of different radii, as clearly shown in Fig. 5. Set screw 41 is screwed in outer sleeve 31 and engages with the step portion of the outer surface 323d at the end thereof to prevent the cup member 323 from rotating in relation to the outer sleeve 31. Accordingly, it is able to keep the coil spring 33 in twisted condition.

The door closing device 30 is removably attached to the pivot hinge 10 by inserting the non-annular end 1 2a of pivot pin 12 into the depression 323c and by also fitting the extending lower end 31 a onto the non-annular peripheral end surface 131 a of door sup- GB 2 033 468A 5 porting plate 13. Thus, the cylinder member 32 is connected with the pivot pin 12 in no relative rotation. And the outer sleeve 31 is also connected with th door supporting plate 13 in no relative rotation. Accordingly, the restoring force of the twisted coil spring 33 is transmitted to the door 21 as a door closing torque.

It is advantageous that door closing device is provided with a door stopper mechanism to 75 keep the door open at an opening angular position.

In the embodiment shown, a ring 52 is fitted onto tubular member 322 of inner cylin der member 32 and is non-rotatably secured thereto by the pins 38. The ring 52 is pro vided with axial slots 52a for receiving pins 38, and, therefore, is axially slidable but non rotatable in relation to the inner cylinder mem ber 32. A coil spring 53 is disposed around the tubular member 322. The upper end of the coil spring 53 engages with the lower end of the ring 52, and the lower end is con nected to the cylinder member 32, for exam ple, by engaging with the upper end of the cup member 323 as shown. Thus, the ring 52 is urged at the highest position limited by the axial slots 52a. The ring 52 is provided with at least one axial projection 52b at the upper end thereof. Two projections are shown in the embodiment.

Two pins 54 corresponding to the axial projections 526 are fixed on the outer surface of the damper shaft 37 to be in contact with the axial upper end of the ring 52.

Referring to Fig. 7, the angular relation between each axial projection 52b and a corresponding pin 54 is so selected that the pin 54 may go over the corresponding axial projection 52b at a time when the door opens at a predetermined door stop angular position such as 90'. Thus, the door is kept open at the predetermined door opening angular posi tion, because the relative rotation of the dam per shaft 37 and the cylinder member 32 is prevented by the engagement between the pin 54 and the axial projection 52b of the ring 52.

The axial projection 52b is preferably formed with a depression 52c at the projec ting end as shown in Fig. 7. When the pin 54 is received in the depression 52c, the door is kept at the door opening angular position without any movement of the door.

In order to close, or further open, the door from this stop position, an external force in direction of door closure, or door opening, must be given to the outer sleeve 31 through the door. As a result, the ring 52 is pushed down against the urging force of the coil spring 53 by the pin 54 going over the projection 52b. So that the door automatically closed by restoring force of the coil spring 33, or is further opening by the external force.

iment shown is similar to the embodiment of Figs. 4-7 except for the door stopper mecha nism. Similar parts are shown by the same reference charaters as in Figs. 4-7, and de scription to the similar parts will be omitted for purposes of simplification of the descrip tion.

A ring member 55 is fitted into the lower end portion of outer sleeve 31 and secured thereto by a spline connection and a screw 56. Another ring member 57 is disposed in the ring 55 and is connected onto the down wardly extending profection 323b of lower cup member 323 by a spline connection. A roller retainer ring 58 is disposed between outer and inner ring members 55 and 57. The roller retainer ring 58 has at least one roller pocket 58a (two pockets are shown) in which a roller 59 is disposed. An end plate 60 is disposed in contact with the lower end of the retainer ring 58 and is secured to the outer ring 55 by an O-ring or a snap ring 61.

Retainer ring 58 has a cut-away portion 58b at the upper end thereof, in which the lower end of coil spring 33 is engage. Therefore, axial movement of retainer ring 58 is re stricted by the spring 33 and the end plate 60. The distance between the outer surface of inner ring 57 and the inner surface of outer ring 55 is shorter than the diameter of roller 59 but longer than the radius of roller 59.

Inner ring 57 has at least one groove 57a (two grooves are shown) for receiving roller 59. The groove 57a angularly extends over a predetermined length. The inner ring 57 has shoulder 57c at the upper end adjacent the groove 57a. Since the shoulder engages with roller, inner ring 57 is prevented from axially removing from the projection 323b of lower cup member 323.

Outer sleeve 31 has a lower extending portion 31 a for fitting onto the non-annular peripheral end surface 131 a of end portion 131 of door supporting plate 13, similar to the embodiment of Figs. 4-7. The extending end 1 2a of pivot pin 12 is formed with a plurality of axial grooves to be connected with inner ring 57 by a spline connection at a time when the extending end 1 2a is fitted into the bore of the inner ring 57.

Therefore, when the door closing device 30 is assembled onto the pivot hinge 10 by fitting inner ring 57 and the lower extending end 31 a of outer sleeve 31 onto the extend ing end 1 2a of pivot pin 12 and the peripheral end surface 131 a of door support ing plate 13, respectively, inner cylinder member 32 is connected with the pivot pin 12 through the inner ring 57, while the outer sleeve 31 is connected with the door support ing plate 13. Therefore, the outer sleeve 31 rotates in relation to the inner cylinder mem ber 32.

Referring to Fig. 9, since rollers 59 are Referring to Figs. 8 and 9, a further embod- 130 received in grooves 57a and are restricted 6 GB 2 033 468A 6 therein by the inner surface of outer ring 55, retainer ring 58 is prevented by the rollers 59 from moving together with outer sleeve 55 thruough coil spring 33. Accordingly, coil spring 33 is twisted by door opening, and the restoring force of coil spring 33 provides door closing torque.

In the shown embodiment, inner ring 57 is also provided with two roller receiving shallow depressions 57b in the outer surface thereof at different angular positions from grooves 57a. And outer ring 55 is also provided with two roller receiving depressions 55a at a predetermined angular position with a depth equal to the depth of the groove 57a. Each pair of these depressions 57a and 55a serves as stopper means incorporating with roller 59. A group of groove 57a, roller 59, depressions 57b and 55a will be described in following description, for purposes of simplification of the description. Similar description will'be applicable will be applicable to another group.

In opening the door, when outer sleeve 31 is rotated from the door closingstate in Fig. 9 to a door opening angular position in Fig. 10, coil spring 33 is twisted so that the restoring force U (shown in Fig. 9) urges roller 59 to push out from groove 57a. Therefore, when outer sleeve 31 further rotates from the state in Fig. 10, roller goes into depression 55a of outer ring 55 as shown in Fig. 11. When outer sleeve 31 further rotates, roller 59 runs along the outer surface of inner ring 57 together with outer ring 55. Accordingly, re- tainer ring 58 also moves together with roller 59 and outer ring 55. Therefore, coil spring 33 is not twisted after roller goes into depressions 55a. When roller 59 arrives depression 57b of inner ring 57 by further door opening, roller 59 is pushed into depression 57b by a centrifugal force N due to the restoring force acting roller 59 through outer ring 55 and retainer ring 58 as shown arrows W.

Referring to Fig. 12, since roller 59 is held in the depression 55a and 57b, roller 59 prevents outer ring 55 from rotating in relation to inner ring 57 and no restoring force acts on the outer sleeve 31 to close the door, so that the door is stopped at the angular position that roller 59 is received in depressions 57b and 55a. In order to move the door from the stop position, an external force overcoming the centrifugal force N must be given through the door. Thus, roller 59 is pushed out from depression 57b and again moved into depression 55a to permit the outer ring 55 to rotate in relation to inner ring 57.

After roller 59 goes into depression 55a, retainer ring 58 moves together with roller 59 and outer ring 55. Therefore, no door closing torque is given to the door at any door opening angular position more than the angu lar position where roller 59 goes from the depression 57a to the depression 55a.

Claims

In the shown embodiment, retainer ring 58130 CLAIMS is provided with a

radial projection 58c adjacent to roller 59 in pocket 58a. The projection 58c is disposed in the corresponding groove 57a to be in contact with roller received in the groove. After roller 59 removed from the groove 57a to fit into depression 55a, the radial projection 58c comes into contact with the end wall 57A-1 of the groove 57a during the further rotation of outer ring 55 by further door opening. Therefore, retainer ring 58 is prevented from rotation together with roller 58 and outer ring 55 as shown in Fig. 1 3,so that coil spring 33 is further twisted by further rotation of outer ring 55 together with the door.

Referring to Figs. 10 and 11, in door opening, after the preceding edge K to the center L of the depression 55a reaches the extension of the line 00' connecting the center 0 of inner ring 57 and the center 0' of roller 59, the moving angle 8 of roller 59 around the inner ring 57 to completely fit into the depression 55a is smaller than the rotating angle 0 of the outer ring 55 and, there- fore, the outer sleeve and the door during the same time. Accordingly, coil spring is still twisted by door opening but less in relation to door opening angle. Thereafter, coil spring 33 is not twisted by further door opening, as above described. During further door opening, coil spring 33 is again twisted after retainer ring 58 is stopped by the engagement of the radial projection 58c with the end wall 57a-1 of the groove 57a.

In the shown embodiment, the depression 57b for stopper mechanism is formed at an angular position within the extent where retainer ring 58 moves together with roller and outer ring.

The screw also serves as a presest screw.

Referring to Fig. 14, the screw 56 is screwed into the gap between inner ring 57 and outer ring 55 to come into contact with peripheral surface of roller 59 under the con- dition that coil spring 59 is twisted. Thus, the rotation of outer sleeve 31 together with outer ring 55 due to the restoring force of coil spring 33 is prevented by the engagement between the roller 59 and the preset screw 56.

When the set screw 56 is loosened after the door closing device 30 is assembled onto the pivot hinge 10, the door is automatically closed by the restoring force of the spring coil 12033.

This invention has been described in detail in connection with preferred embodiments, but these are merely example only and this invention is not restricted thereto. It will be easily underatood by those skilled in the art that the other variations and modifications can be easily made within the scope of this invention.

7 GB 2 033 468A 7 1. An offset pivot hinge having a door closing device releasably mounted thereon, wherein said offset pivot hinge has a first plate member for securing to one of a door and a floor or a door frame, a pivot pin secured to one end portion of said first plate member, and a second plate member for securing to the other of the door and the floor or the door frame, the second plate member being pivoted at one end portion thereof on said pivot pin, and said closing device comprises an outer sleeve which is releasably mounted at one end thereof on said second plate member, an inner member which is mounted in said outer sleeve for rotation relative to said outer sleeve and is releasably connected to said pivot pin, and a coil spring member which is disposed within said outer sleeve, one end of said spring member being connected to said outer sleeve and the other end of said spring member being connected to said inner member so that said spring member may be twisted by a relative rotation between said outer sleeve and said inner member to provide a door closing torque.

2. An offset pivot hinge having a door closing device as claimed in claim 1, wherein said door closing device further comprises a damping mechanism for reducing the door closing speed which comprises an oil containing cylinder member and a piston member fitted into said cylinder member, said cylinder member being secured to said inner member and being rotatably supported within and relative to said outer sleeve, said piston member being reciprocable within said cylinder member upon relative rotation between said inner member and said outer sleeve, said piston member being provided with a check valve which permits a unidirectional oil flow from a first side to a second side of said piston member and an oil hole which permits oil flow in both directions between respective opposite sides of said piston member, and said check valve preventing the oil from flowing therethrough at a time when said piston member moves in a direction corresponding to door closure, whereby the door closing speed is reduced.

3. An offset pivot hinge having a door closing device as claimed in claim 2, wherein said door closing device further comprises a shaft member secured at one end thereof to said outer sleeve and extending at the other end into said cylinder member, said piston member being non-rotatably but axially slidably mounted on said extending portion of said shaft member, while said piston member is threadably engaged in said cylinder member, whereby said piston member is reciprocated within said cylinder upon relative rotation between said outer sleeve an said inner member.

4. An offset pivot hinge with a door closing device as claimed in claim 3, wherein said shaft member has an axially extending hole, a manually operable rod is rotatably disposed within said axial hole of said shaft member and is secured to said shaft member, a movable member is disposed in said axial hole of said shaft member, said movable member is threadably engaged with one of the extending end of said operating rod and said shaft member while being connected to the other -of the extending end of said operating rod and said shaft member so as to be non-rotatably but axially slidable in a direction determine by the direction of rotation of said manually operable rod, and an adjuster rod is secured to said movable member and extends therefrom into said cylinder through said oil hole of said piston member, said adjuster rod being milled to form a tapered surface, whereby a lateral dimension of an oil passage through said oil hole, alongside said tapered surface, may be changed by the operation of said operable rod, thereby to adjust the door clos- ing speed.

5. An offset pivot hinge having a door closing device as claimed in claim 1, wherein said outer sleeve is formed with a plurality of first axial projections as said one end, said inner member has a second axial projection at the same end, said second projection is formed with a non-annular first depression in a projecting end surface thereof, said second plate is formed with second depressions which receive respective first projections, said second plate has at least one set screw means for securing said first projections in said seond depressions, and said pivot pin has an extending end of non-annular section for mating with said first depression, whereby said door closing deice may be easily removed by axially drawing said device away from said pivot hinge after loosening said set screw means.

6. An offset pivot hinge having a door closing device as claimed in claim 1, wherein said second plate is formed with a non-annular surface at a peripheral end of said one end portion thereof where said seond plate is pivoted on said pivot pin, said pivot pin has an extending end of a non-annular section, said outer sleeve is provided with an extending end which has a non-annular inner surface at said one end thereof for fitting into said non-annular surface of said second plate, said outer sleeve has at least one set screw means for securing said extending end of said outer sleeve to said second plate, and said inner member has an axial projection which is formed with a non-annular depression in a projecting end surface thereof, in which depression said extending end of said pivot pin is fitted, whereby said door closing device may be easily removed by axially drawing said device away from said pivot hinge after loosening said screw means.

8 GB 2 033 468A 8 7. An offset pivot hinge having a door closing device as claimed in claim 1, wherein said door closing device further comprises a ring member which is axially slidably connected to said inner member and has at least one axial projection at a predetermined angular position, a spring member for urging said ring member in the direction of said projection, and at least one pin member correspond- ing to said projection and secured to said outer sleeve so that said pin member may ride over said projection during the relative rotation of said outer sleeve and said inner member, whereby the door is kept open by engagemen of said projection with said pin member.

8. An offset pivot hinge having a door closing device as claimed in claim 1, wherein said door closing device further comprises a preset screw member radially screwed into said outer sleeve so as to fix said inner member in a condition such that said coil spring is twisted by a predetermined angle, whereby the restoring force of sai coil spring provides a sufficient door closing torque after said preset screw is loosened.

9. An offset pivot hinge having a door closing device as claimed in claim 1, where said door closing device further comprises a first ring member which is fixedly secured in said outer sleeve and has at least one depression formed in an inside surface thereof, a second inner ring member is fixedly secured on said inner member and is disposed inside said first ring with an annular gap therebetween, said second inner ring member has at least one groove of a depth equal to the depth of said depression in said first ring member but smaller than the width of said annular gap in an outer surface thereof which extends angularly over a predetermined extent and at a predetermined angular position different from that of said depression in said first ring member, at least one roller member having a diameter equal to the total amount of the depth of said groove and said annular gap is disposed in said groove, a roller retainer ring having at least one roller pocket for containing said roller member is rotatably dis- posed within said annular gap, and said retainer ring is connected to said other end of said coil spring so that said other end of said coil spring is connected to said inner member through said roller member and said second inner member, whereby said coil spring may be twisted during door opening before said depression in said first ring reaches said roller member in said groove so that said roller is pushed out from said groove into said depres- sion, and said coil spring may be not twisted thereafter.

10. An offset pivot hinge having a door closing device as claimed in claim 9, wherein said second inner ring has an additional depression shallower than said groove in the outer surface thereof at a predetermined angular position displaced from said groove in the direction of rotation of said first ring during door opening, whereby said roller member received in said depression of said first ring during door opening may be partially pushed into said additional depression to keep the door opening thereat.

11. An offset pivot hinge having a door closing device as claimed in claim 9, wherein said retainer ring has a radial projection adjacent to said roller member, and said radial projection extends into said groove of said second inner ring so as to engage with the end wall of said groove after said roller member is pushed out from said groove into said depression of said first ring, whereby said coil spring may be again twisted by further door opening.

12. An offset pivot hinge having a door closing device as claimed in claim 9, wherein said second inner ring is fitted onto said inner member and non-rotatably connected thereto by a spline connection, and said pivot pin is fitted into said second inner ring and nonrotatably but axially removably connected thereto by a spline connection.

13. An offset pivot hinge having a door closing device as claimed in claim 9, wherein said first ring is non-rotatably connected to said outer sleeve by a spline connection and is prevented from axially moving by at least one screw means which is radially screwed into said outer sleeve and said first ring, said screw means is screwed into said annular gap to engage with said roller member so that the rotation of said outer sleeve may be prevented in the direction corresponding to the door closure under the condition that said coil spring is twisted by a predetermined degree, whereby the door closing torque enough to completely close the door may be obtained at a time when said screw means is loosened to remove the engagement of said roller member and said screw means.

14. A pivot hinge having a door closing device releasably mounted thereon, wherein said pivot hinge has a first plate member for securing to one of a door and a floor or a door frame, a pivot pin secured to said first plate member, and a second plate member for securing to the other of the door and the floor or the door frame, the second plate member being pivoted on said pivot pin, and said closing device comprises an outer sleeve which is releasably mounted on one of said second plate member and said pivot pin, an inner member which is mounted in said outer sleeve for rotation relative to said outer sleeve and is releasably connected to the other of said second plate and said pivot pin, and a spring member which is disposed within said outer sleeve, said spring member being connected between said outer sleeve and said inner member so that said spring 9 GB 2 033 468A 9 member may be deformed by a relative rotation between said outer sleeve and said inner member to provide a door closing torque.

15. A pivot hinge constructed, arranged and adapted to operate substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd-1 980. Published at The Patent Office, 25 Southampton Buildings, London, WC2A 'I AY, from which copies may be obtained.

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